Yeah that's the message I got too. The terminal command in question is harmless, and OP explicitly says this along with saying it was transparent about what it is doing, but the point is to be wary of blindly pasting terminal commands if you are unsure about exactly what they do. It takes five seconds to paste them into Google before running them on your system.

It wasn't that long ago people were posting shit like "make your Mac 10x faster by running rm -rf ~/" and "delete system32 it's a virus" and yes people actually fell for that shit.

When people get into the habit of blindly trusting terminal commands without understanding what they're doing, they can easily fuck their shit up.

The tl;dr is simply "don't trust, verify."